patch 8.2.0517: Vim9: cannot separate "func" and "func(): void"

Problem:    Vim9: cannot separate "func" and "func(): void".
Solution:   Use VAR_ANY for "any" and VAR_UNKNOWN for "no type".
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 237b024..b7ec979 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -2239,6 +2239,7 @@
 	case VAR_BLOB:
 	    return tv->vval.v_blob != NULL && tv->vval.v_blob->bv_ga.ga_len > 0;
 	case VAR_UNKNOWN:
+	case VAR_ANY:
 	case VAR_VOID:
 	    break;
     }